A method of determining a useful skew for a circuit design includes computing a slack value for each sequential cell in the circuit design, identifying modifiable sequential cells in the circuit design, and computing a target delay for each modifiable sequential cell. One or more sequential cells are discarded based on the slack values. A target slack value for each remaining sequential cell is determined. The remaining cells are sorted based on the target slack values to determine a minimum target slack value, and a delay for each cell is determined based on the minimum target slack value.